I have a 2001 2500 24 valve cummins with over 320,000 miles. I recently moved and pulled a trailer 4 hours to the new house. I parked the truck in the drive way left for 5 minutes came back and it shut itself off. I tried to start it again to move it. When I turned the key no warning lights came up or glow plug lights nothing I turned key to start and nothing happens except 1 really quiet click in the fuse box under the hood. I've checked all fuses and they are good I took the batteries out and had them tested under load and their good I took the starter out and had it tested and it's good and now I'm clueless and I start my new job in 4 days and need the truck. Any help is greatly appreciated.

 

This might sound stupidly simple, but what do your battery cable connections look like? If they are really dirty, or loose, that could cause some issues

 

when you hear that "click" but nothing else it's cause there is not enough power to engage the starter could be a bad ground a lost cable as stated above or a wire somewhere with the shith worn off and it's grounding out my best guess would be a caroded ground wire on the frame block or fire wall or a dead short somewhere draining the voltage. best of luck hope this helps